Method for measuring internal stress of concrete structure

Abstract

The invention relates to a method for measuring internal stress of a concrete structure, which comprises the following steps of: detecting elastic modulus: manufacturing a first concrete test piece by adopting concrete with the same proportion as a concrete member, and measuring tensile elastic modulus E (t) of the first concrete test piece at different ages; detecting a strain difference: detecting a differential strain epsilon difference (t) between the first vibrating wire strain gauge and the concrete members at different ages; detecting the comprehensive strain of the concrete member; measuring the comprehensive strain epsilon < comprehensive > (t) of each point of the concrete member; and detecting the internal stress of the concrete member: rejecting the differential strain epsilon difference (t) caused by the difference between the first vibrating wire strain gauge and the thermal expansion coefficient of the concrete from the measured comprehensive strain epsilon set (t), and then combining the tensile elastic modulus E (t) of the concrete member at different ages to obtain the internal stress of the concrete member at different ages. According to the invention, errors of internal stress detection of the concrete member can be effectively reduced.

Description

technical field [0001] The application relates to the field of engineering detection methods, in particular to a method for measuring the internal stress of a concrete structure. Background technique [0002] Due to the heat of hydration of concrete, its own volume deformation, shrinkage and creep, and the influence of external temperature changes, concrete members will expand and shrink, and the deformation of concrete members is constrained by surrounding members, such as shear walls or concrete columns. , cannot be freely strained to generate stress in the concrete member. When the stress in the concrete member is greater than the tensile strength of the concrete member, the concrete member will appear cracks. Therefore, it is necessary to detect the stress inside the concrete member before and after the construction to reflect the internal situation of the concrete member. [0003] When detecting the internal stress of concrete members, some calculation formulas can be...

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Problems solved by technology

[0005] However, when measuring the stress in concrete members, due to the real-time changes in the concrete hydration heat temperature, the strain measured by the vibrating wire strain gauge is actually the superposition of the actual strain of the concrete and other corrected deformations. There is a certain difference between the different strains of the concrete member and the actual strain of the concrete member, which leads to a certain error in the stress detection inside the concrete member

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